“You don’t stop in midstream on something that has been very effective,” Rice told a news conference Wednesday night after a meeting with President Alvaro Uribe. “It took a long time to get this program started, and it’s going to take a little while to eliminate the problem.”

Rice was ending her visit to Colombia on Thursday and planned to fly to Chile for a meeting of the Community of Democracies, a group of more than 100 countries that seeks to expand democratic rule around the world.

She was scheduled to address the group Thursday evening.

Massive aid program, but to what end?The United States has provided more than $3 billion in assistance to Colombia since 2000 on counternarcotics and counterinsurgency programs and on programs to improve the criminal justice system.

A centerpiece of the counterdrug program has been an eradication strategy aimed principally at coca, the main ingredient in cocaine.

After two years of encouraging results, data released last month showed that the total area under coca cultivation — 281,000 acres — remained essentially the same in 2004 compared with 2003 in spite of a massive spraying campaign.

Critics suggested the spraying campaign wasn’t getting the job done. They contend that coca growers have been able to neutralize spraying by cultivating new areas or developing herbicide-resistant strains.

About 90 percent of the cocaine consumed in the United States comes from Colombia.

No time to quit, Rice saysRice, perhaps focusing on the positive three-year trend in eradication, said, “I don’t think it is time to abandon a strategy that is both diminishing the crop here and a strategy that is restoring the democratic security of Colombia.”

That was a reference to U.S. efforts to help Colombia defeat three armed insurgencies, the largest of which is the leftist FARC rebel group.

On the justice front, Rice said the government had corralled a record number of drug traffickers. She also said extraditions of Colombian traffickers to the United States are up since Uribe took office in 2002. According to the U.S. Embassy, the figure during that period is 214.

Rice began her Latin American tour on Tuesday in Brazil. Her final stop will be El Salvador on Friday.